Desperate bladder play means holding in urine until the limit and savoring the overwhelming relief of finally letting go. One afternoon, Kana returns from shopping but cannot find her key. Unable to hold it any longer, she wets herself outside the front door. Her adult nephew Kazuya, who lives nearby, happens to witness the humiliating scene. Unable to erase the image from his mind, he begins lying in wait for her, drawing Kana into a fetish she can never reveal to her husband.